A direct tire inflation pressure detection device is one type of tire inflation pressure detection device in the related art. The direct tire inflation pressure detection device is formed by directly attaching transmitters each including a sensor, such as a pressure sensor, to tired-wheels side and attaching an antenna and a receiver to a vehicle body side. The tire inflation pressure detection device performs a tire inflation pressure detection when the transmitters transmit detection results of the pressure sensors and the receiver receives the detection results via the antenna.
Because it is not preferable to run a vehicle with tires at a low tire inflation pressure, it is required for the tire inflation pressure detection device as above to promptly notify a driver of a decrease of the tire inflation pressure.